34 results on '"Bastien-Masse, Maléna"'
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2. Reusability Assessment of Obsolete Reinforced Concrete Structural Components
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Devènes, Julie, Bastien-Masse, Maléna, Küpfer, Célia, Fivet, Corentin, di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Ilki, Alper, editor, Çavunt, Derya, editor, and Çavunt, Yavuz Selim, editor
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- 2023
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3. Reuse of concrete components in new construction projects: Critical review of 77 circular precedents
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Küpfer, Célia, Bastien-Masse, Maléna, and Fivet, Corentin
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- 2023
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4. Re:Crete – Reuse of concrete blocks from cast-in-place building to arch footbridge
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Devènes, Julie, Brütting, Jan, Küpfer, Célia, Bastien-Masse, Maléna, and Fivet, Corentin
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- 2022
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5. Reuse of concrete components in new construction projects: Critical review of 77 circular precedents
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Küpfer, Célia Marine, Bastien Masse, Maléna, Fivet, Corentin, Küpfer, Célia Marine, Bastien Masse, Maléna, and Fivet, Corentin
- Abstract
Extracting pieces of concrete from obsolete buildings and reusing them, as is, in new assemblies is today rarely considered a strategy for improving the sustainability of the construction sector. By delaying the crushing of concrete into aggregates and avoiding the need for fresh cement in new buildings, the circular strategy is however expected to reduce greenhouse gas emissions and threats to natural ecosystems. In reaction, the authors postulate that (1) built precedents of Piecewise Reuse of Extracted Concrete in new Structures (PRECS) have existed for several decades, (2) a large diversity of proven implementation techniques is readily available but knowledge is fragmented, (3) barriers to a broader adoption can be inferred from the existing documentation and are largely transitional. To support these postulates, this study first builds an original collection of 77 PRECS projects designed between 1967 and 2022 in Europe and the U.S.A. Next, a diachronic analysis determines seven historical trends and three periods since 1967, shedding new light on the development of PRECS and its design possibilities. Supporting and limiting forces for a broader adoption of PRECS are then identified through a synchronic analysis. Recommendations for future research directions are also given. In conclusion, this paper demonstrates that the reuse of concrete components is a practice with already a long history and several successful operations in terms of environmental impact and cost, which hence supports the potential of PRECS to become a more widespread strategy of cleaner construction.
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- 2023
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6. Composite model for predicting the punching resistance of R-UHPFRC–RC composite slabs
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Bastien-Masse, Malena and Brühwiler, Eugen
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- 2016
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7. Effect of fiber orientation on the in-plane tensile response of UHPFRC reinforcement layers
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Bastien-Masse, Malena, Denarié, Emmanuel, and Brühwiler, Eugen
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- 2016
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8. Basel – Socinstrasse 55a, 57 and 59 – Resource assessment of structural components
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Devènes, Julie, Widmer, Nicole, and Bastien-Masse, Maléna
- Subjects
ressource assessment ,concrete ,existing structures ,reuse - Abstract
The buildings located in Socinstrasse 55a, 57 and 59 are three buildings erected between 1960 and 1965. Cast-in-place slabs, columns, walls form the main load-bearing structure of the building. The facade is partly made of precast concrete panels. A new project is planned, and it implies the demolition of building 59 and a facade of building 55a. Little-known and rarely implemented, the reuse of concrete components from obsolete buildings in new projects is a sustainable approach that promotes a circular economy. When reusing, the components of obsolete buildings are carefully dismantled without being crushed. They are then cleaned, possibly repaired, or trimmed, and reassembled with little transformation in a new project, maintaining their shapes and structural properties. In addition to maintaining the embodied energy and history of the reused components, reuse allows the construction industry to reduce demolition waste, greenhouse gas emissions, and material consumption. This report is a preliminary resource assessment and aims at inventorying and assessing all structural components of the planed-to-be-demolished parts of buildings situated in Socinstrasse 55a to 59, focusing on their potential value for reuse. Precast concrete facade panels and cast-in-place RC components are included. The assessment methodology, detailed in a complementary report, allows identifying all properties needed to evaluate the potential for reuse of a RC component: geometry, material properties, resistance, current condition, accessibility, future durability, aesthetics and environmental impacts. After reviewing available reports and drawings on the building, onsite visits are carried out to complete the information and visually inspect the structural components. During the inspection, the components are assessed with regards to their suitability for reuse and their condition is classified into a five-grade scale. Destructive and non-destructive investigations are also carried out to verify the material properties and the geometry and rebar layout of the RC components. Concrete cores are extracted to verify the compressive strength, local openings are made in the cover concrete to check the rebar layout and ground penetrating radar scans are done over a complete floor slab to verify the rebar spacing and concrete cover. The planed-to-be-demolished components represent approximately 800 m3 of material constituting the load-bearing system, with approximately 50 m3 of precast concrete and 750 m3 of cast-in-place concrete. The components of the building load-bearing structure are considered in good condition during a visual inspection and are assessed as mostly suitable for structural reuse. Using the results of the destructive and non-destructive investigation and knowledge on the historical construction methods of such buildings, it was also possible to validate the rebar layout in most of the slab zone areas of building Socinstrasse 59. This knowledge increases the potential for a future reuse of the slab components. The inventoried components are divided into 6 categories: (1) facade components; (2) slab components; (3) column components; (4) wall components; (5) staircases and (6) timber roof structure. For each of these categories a complete factsheet is prepared, including pictures, drawings and useful information on their condition. The volume and weight of each component types are given, as well as their share of the total material volume. The embodied global warming potential (in kgCO2eq and kWhoil-eq) for fabrication and demolition of the components is also calculated. This document should serve as a base for designing and planning future reuse applications for the concrete components extracted when deconstructing the buildings in Socinstrasse 55a, 57 and 59. The information presented here will help planners to prioritize the reuse strategy on the components in the best conditions, with the largest volume share and thus with the largest embodied global warming potential.
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- 2023
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9. Bestandsanalyse für die Wiederverwendung von tragenden Stahlbetonbauteilen
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Devènes, Julie, Bastien-Masse, Maléna, and Fivet, Corentin
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concrete ,resource assessment ,existing structures ,reuse - Abstract
Heutzutage werden viele Stahlbetonbauten, die meist keine oder nur geringe strukturelle Defekte aufweisen, aus sozioökonomischen Gründen abgerissen. Wenn die Erhaltung eines bestehenden Gebäudes nicht möglich ist, erlaubt die Wiederverwendung der tragenden Bauteile in einem neuen Projekt, die schädlichen Umweltauswirkungen des Rück- und Neubaus zu verringern. Die Bauteile des obsoleten Gebäudes werden dabei sorgfältig demontiert, ohne sie zu Schutt zu zerkleinern. Sie werden gereinigt, möglicherweise repariert oder eingepasst und wiederverwendet, wobei ihre ursprüngliche Geometrie und ihre Eigenschaften so weit wie möglich erhalten bleiben. Die Anwendung dieser alternativen Strategie erfordert Änderungen im Planungsprozess der Abriss- und Neubauprojekte. Als Grundlage dafür muss das obsolete Bauwerk inventarisiert und analysiert werden, um die mechanischen und geometrischen Eigenschaften sowie die Dauerhaftigkeit der Stahlbetonbauteile zu bestimmen und ihre Wiederverwendbarkeit zu beurteilen. Das vorliegende Dokument beschreibt eine Methodik zur Beurteilung der Wiederverwendbarkeit und ein Verfahren für die Bestandsanalyse eines Stahlbetonbauwerk, das demnächst rückgebaut werden soll. Um den Planern beim Prüfen der verschiedenen Wiederverwendungsmöglichkeiten für ein Bauteil zu helfen, wird zunächst ein Werkzeug zur Beurteilung der Wiederverwendbarkeit vorgestellt. Es basiert auf den vorhandenen Schäden des Bauteils, seiner zukünftigen Nutzung und den für die Instandsetzung der Bauteile erforderlichen Massnahmen. Die Schadensbewertung wird vor dem Rückbau des Spendergebäudes durchgeführt. Die Nutzungsklasse - die die künftige Beanspruchung des Bauteils ausdrückt - und die Massnahmenklasse - die den Unterhalt und die nötigen Anpassungen des Bauteils beschreibt - hängen vom Bau des Empfängergebäudes ab. Nach der Klassifizierung der Schäden, Nutzung und Massnahmen eines Bauteils ergibt sich der Wiederverwendbarkeitsgrad, der eine Empfehlung für die Wiederverwendung und die damit verbundenen Kontrollen im Empfängergebäude ausdrückt. Diese Methodik zur Beurteilung der Wiederverwendbarkeit soll die Subjektivität der Analyse des Wiederverwendungspotenzials von Stahlbetonbauteilen verringern. In diesem Bericht werden die Schritte zur Durchführung einer vollständigen Bestandsanalyse von Stahlbetonbauwerken und deren Bauteilen beschrieben. Die Bestandsanalyse sammelt alle Informationen, die zur Beurteilung und Planung der zukünftigen Wiederverwendung der Bauteile erforderlich sind: Kategorisierung und Quantifizierung der Bauteile, Einstufung der vorhandenen Schäden, Untersuchungen der Geometrie und der Materialeigenschaften sowie Ermitteln weiterer Merkmale (Ästhetik, Zugänglichkeit, Tragwiderstand, Umweltauswirkungen). Diese systematische Methodik hat zum Ziel, die Subjektivität einer solchen Analyse zu verringern. Die hier beschriebenen Methodiken und Verfahren ermöglichen es, den Rückbau eines veralteten Stahlbetonbauwerks zu planen und dabei Mittel anzuwenden, die die Wiederverwendung der Bauteile mit dem grössten Potenzial begünstigen. Sie liefern auch die Informationen für die vorläufige Planung eines Empfängerbauwerks. In späteren Planungsphasen können zusätzliche Untersuchungen am Bestand erforderlich sein., See also English version. DOI: 10.5281/zenodo.7457909
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- 2022
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10. Resource assessment for the reuse of load-bearing reinforced concrete components
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Devènes, Julie, Bastien-Masse, Maléna, and Fivet, Corentin
- Subjects
concrete ,resource assessment ,existing structures ,reuse - Abstract
Today, many reinforced concrete structure, most of the time with no or small structural disturbances, are demolished for socio-economic reasons. When the preservation of an existing building is not possible, reusing the structural component in a new project is a strategy that allows the diminution of the detrimental environment impacts of deconstruction and new construction. The components of the obsolete building are carefully dismantled without being crushed. They are cleaned, possibly repaired or trimmed and reused while maintaining as much as possible their pre-existing geometry and properties. Adopting this alternative strategy implies changes in the design processes of the demolition and new construction projects. As a starting point, the obsolete existing structure must be inventoried and assessed to define the mechanical and geometrical properties as well as the durability of its reinforced concrete components and to evaluate their reusability. The present document describes a reusability assessment method and a resource assessment protocol for a soon-to-be deconstructed RC structure. To help the designers evaluate the different reuse options for a component, a reusability assessment tool is first presented. It is based on the pre-existing damages of the component, its future use and the intervention required to rehabilitate the components. The damage assessment is conducted before the deconstruction of the donor building. The use class – expressing the structural demand for the component – and the intervention class – describing maintenance and modifications on the component – depend on the design of the receiver building. Once the damage, use and intervention of a component have been classified, the reusability grade is obtained, expressing recommendation for the reuse and the related monitoring in the receiver structure. This reusability assessment tool is intended to reduce the subjectivity of the assessment of reuse potential of RC components. This report then describes the steps to carry out the complete resource assessment of reinforced concrete structures and their components. The resource assessment collects all information needed to evaluate and plan the future reuse of the components: classification and quantification of the components, grading of their pre-existing damages, investigations on their geometrical and material properties and evaluation of their qualities (aesthetics, accessibility, resistance, environmental impact). This systematic methodology aims at reducing the subjectivity of such an assessment. The methods and protocols described herein allow planning the deconstruction of an obsolete RC structure using methods that will subsequently facilitate the reuse of the components with the most potential. They also give the information for preliminary designs of a receiver structure. In later design stages, additional investigations on the stock might be required., See also German version. DOI: 10.5281/zenodo.7457954
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- 2022
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11. Basel – Lagerhalle Erlenmatt Ost – Resource assessment of structural components
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Devènes, Julie, Bastien-Masse, Maléna, and Fivet, Corentin
- Subjects
ressource assessment ,concrete ,existing structures ,reuse - Abstract
The Lagerhalle Erlenmatt Ost is a 3-story building (basement, ground floor and two upper floors) used for food storage, located in Erlenmatt district in Basel and erected in 1975. Cast-in-place reinforced concrete (RC) slabs, walls, and mushroom columns form the main load-bearing structure of the building. The self-supporting facade is made of lightweight expanded clay aggregate (LECA) concrete panels. The deconstruction of this building is planned, thus making available a large amount of RC components composing the structure and the facades. Little-known and rarely implemented, the reuse of concrete components from obsolete buildings in new projects is a sustainable approach that promotes a circular economy. When reusing, the components of obsolete buildings are carefully dismantled without being crushed. They are then cleaned, possibly repaired or trimmed, and reassembled with little transformation in a new project, maintaining their shapes and structural properties. In addition to maintaining the embodied energy and history of the reused components, reuse allows the construction industry to reduce demolition waste, greenhouse gas emissions, and material consumption. This report is a preliminary resource assessment and aims at inventorying and assessing all structural components of the Lagerhalle Erlenmatt Ost, focusing on their potential value for reuse. Interest is mainly in the precast LECA concrete facade panels, but cast-in-place RC components are briefly included. The assessment methodology, detailed in a complementary report, allows identifying all properties needed to evaluate the potential for reuse of a RC component: geometry, material properties, resistance, current condition, accessibility, future durability, aesthetics and environmental impacts. After reviewing available reports and drawings on the building, onsite visits are carried out to complete the information and visually inspect the structural components. During the inspection, the components are assessed with regards to their suitability for reuse and their condition is classified into a five-grade scale. The building is made up of approximately 4 700 m3 of material constituting the load-bearing system, with approximately 450 m3 of precast LECA concrete and 4 250 m3 of cast-in-place concrete. The LECA panels are damaged and are assessed as unsuitable for structural reuse. The other components of the building load-bearing structure are considered in good condition by a first preliminary visual inspection. However, they would require further detailed investigations to gather all data needed to plan a potential future reuse. The inventoried components are divided into 5 categories: (1) facade components; (2) slab components; (3) wall components; (4) column components; and (5) staircases. For each of these categories a complete factsheet is prepared, including pictures, drawings and useful information on their condition. The volume and weight of each component types are given, as well as their share of the total material volume. The embodied global warming potential (in kgCO2eq and kWhoil-eq) for fabrication and demolition of the components is also calculated. This document should serve as a base for designing and planning future reuse applications for the concrete components extracted when deconstructing the Lagerhalle Erlenmatt Ost. The information presented here will help planners to prioritize the reuse strategy on the components in the best conditions, with the largest volume share and thus with the largest embodied global warming potential.
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- 2022
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12. Re:Crete – reuse of concrete elements in new structures: A footbridge prototype
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Brütting, Jan, Devènes, Julie Rachel, Küpfer, Célia Marine, Bastien Masse, Maléna, and Fivet, Corentin
- Abstract
Concrete accounts for the largest share of worldwide building material use and waste generation, with cement production being responsible for approximately 9% of global anthropogenic CO2 emissions. A currently untapped strategy to significantly reduce these environmental impacts consists in reusing reinforced concrete (RC) elements in new load-bearing applications. This paper presents a new design-and-build concept to reuse cast-in-place RC wall and slab elements sourced from obsolete buildings. The applicability of the proposed paradigm is demonstrated through a prototype: a 10-m spanning post-tensioned segmental arch made of 25 reclaimed concrete blocks. The paper illustrates the complete workflow, including the sourcing of the blocks through sawing and the prototype assembly. A comparative Life Cycle Assessment shows that the prototype structure has a significantly lower environmental impact than equivalent designs made of new material.
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- 2022
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13. Re:crete – a Footbridge Made of Reused Concrete Blocks
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Devenes, Julie, primary, Brütting, Jan, additional, Bastien-Masse, Maléna, additional, Küpfer, Célia, additional, and Fivet, Corentin, additional
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- 2022
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14. Zürich Stadtspital Triemli Personalhäuser – Resource assessment of structural elements
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Devènes, Julie, Bastien-Masse, Maléna, Küpfer, Célia, and Fivet, Corentin
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concrete ,resource assessment ,resource diagnostic ,reuse - Abstract
The Triemli Personalhäuser are three equal 15-story buildings located on the Zürich Triemli Stadtspital campus and erected between 1964 and 1969. Cast-in-place reinforced concrete (RC) slabs and walls form the building cores and their surrounding corridors. The rooms are arranged around these cores. The load-bearing intermediate walls, made of prefabricated masonry, support thin precast slabs used as permanent forms. A RC layer is cast over these precast slabs and connects the room slabs with the cast-in-place slabs of the corridors and cores. The self-supporting facade consists of precast RC panels. The City of Zürich plans the deconstruction of these three buildings, thus making available a large amount of RC elements composing the structure and the facades of these buildings. Little-known and rarely implemented, the reuse of concrete elements from obsolete buildings in new projects is a sustainable approach that promotes a circular economy. When reusing, the components of obsolete buildings are carefully dismantled without being crushed. They are then cleaned, possibly repaired or trimmed, and reused without many transformations in a new project, maintaining their shapes, technologies, and mechanical properties. In addition to maintaining the embodied energy and history of the reused components, reuse allows the construction industry to reduce demolition waste, greenhouse gas emissions, and material consumption. This report is a preliminary resource assessment and aims at inventorying and assessing all structural elements of the Triemli Personalhäuser, focusing on their potential value for reuse. Both precast and cast-in-place RC elements are included. They are part of the load-bearing structure or are self-supporting such as the precast facade elements. The proposed methodology allows identifying all properties needed to evaluate the potential for reuse of an element: geometry, material properties, current condition, aesthetics, accessibility, resistance, future durability and environmental impacts. After reviewing available reports and drawings on the buildings, onsite visits are carried out to complete the information and visually inspect the structural elements. During the inspection, the elements are assessed with regards to their suitability for reuse and their condition is classified into a five-grade scale. The investigations are completed with destructive and non-destructive testing of the material properties. Together, Buildings A, B and C are made up of approximately 7 000 m3 of materials constituting their load-bearing system, with approximately 2 500 m3 of precast concrete, 3 400 m3 of cast-in-place concrete and 1 100 m3 of masonry. Of this total, approximately 4% of the volume is dropped from the analysis due to the bad condition of the elements, namely the balcony slabs, the roof slab, and the external stairs. The other elements are in a good or acceptable condition and ae inventoried and analysed in detail. The inventoried elements are divided into 5 categories: (1) facade elements; (2) slab elements; (3) wall elements; (4) column elements; and (5) staircases. Each of these categories are subdivided into a certain number of element types for which a complete factsheet is prepared, including pictures, drawings and useful information on their condition. The volume and weight of each element types are given, as well as their share of the total material volume. The embodied global warming potential (in kgCO2eq) for fabrication and demolition of the elements is also calculated. The results of the investigation on material properties confirm sufficient compressive strength for all elements. The carbonation depths measured on the cores are lower than the cover thickness of the reinforcement. Thus, the concrete is not carbonated in the reinforcement areas and the risk of corrosion is kept low, insuring a good durability of the elements. This document should serve as a base for designing and planning future reuse applications for the concrete elements extracted when deconstructing the Triemli Personalhäuser. The information presented here will help the planners to prioritize the reuse strategy on the elements in the best conditions, with the largest volume share and thus with the largest embodied global warming potential.
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- 2022
- Full Text
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15. Tensile basic creep versus compressive basic creep at early ages: comparison between normal strength concrete and a very high strength fibre reinforced concrete
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Rossi, Pierre, Charron, Jean Philippe, Bastien-Masse, Maléna, Tailhan, Jean-Louis, Le Maou, Fabrice, and Ramanich, Sandrine
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- 2014
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16. Environmental and economic analysis of new construction techniques reusing existing concrete elements: two case studies
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Küpfer, Célia Marine, Bastien Masse, Maléna, Devènes, Julie Rachel, and Fivet, Corentin
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life-cycle analysis ,construction cost ,circular economy ,cast-in-place concrete ,General Medicine ,General Chemistry ,reuse - Abstract
As the most widely used construction material worldwide, concrete is the main cause of greenhouse gas emissions, material depletion, and waste generation by the construction industry. Typically, concrete waste is crushed and, at best, reclaimed into recycled aggregate or used as gravel. This process is energy-intensive and results in a reduction in material properties. In contrast, the direct reuse of concrete elements from obsolete structures offers great potential for significantly reducing the environmental impact of new constructions. To be reused, concrete elements are carefully sawn out of soon-to-be-demolished buildings. Elements are then used without other major transformations for another service cycle in a new assembly. This paper analyses two recent projects in Switzerland that showcase innovative applications of concrete reuse: a post-tensioned segmented arch footbridge and a parking pavement. Both projects reuse blocks extracted from cast-in-place concrete buildings undergoing transformation or demolition. In this paper, environmental and economic analyses provide a comprehensive understanding of the alleviations and costs involved. Results are compared to those of alternatives with conventional construction methods. The two projects reusing concrete globally showcase a drastically lower environmental impacts for comparable or higher construction costs, hence calling for future developments of such new circular construction strategies.
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- 2022
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17. Strengthening Paudèze bridges decks using UHPFRC struts
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Menétrey, Philippe, primary, Moreillon, Lionel, additional, and Bastien-Masse, Maléna, additional
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- 2019
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18. Punching resistance of flat slabs strengthened with an added layer of UHPFRC
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Bastien-Masse, Maléna, primary and Einpaul, Jürgen, additional
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- 2017
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19. Strengthening the Chillon viaducts deck slabs with reinforced UHPFRC
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Brühwiler, Eugen, primary, Bastien-Masse, Maléna, additional, Mühlberg, Hartmut, additional, Houriet, Bernard, additional, Fleury, Blaise, additional, Cuennet, Stéphane, additional, Schär, Philippe, additional, Boudry, Frédéric, additional, and Maurer, Marco, additional
- Published
- 2015
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20. Tensile basic creep versus compressive basic creep at early ages: comparison between normal strength concrete and a very high strength fibre reinforced concrete
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Rossi, Pierre, primary, Charron, Jean Philippe, additional, Bastien-Masse, Maléna, additional, Tailhan, Jean-Louis, additional, Le Maou, Fabrice, additional, and Ramanich, Sandrine, additional
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- 2013
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21. Concrete bridge deck slabs strengthened with UHPFRC
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Bastien-Masse, Maléna, primary and Brühwiler, Eugen, additional
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- 2013
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22. Characterization of the UHPFRC S3-13
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Bastien Masse, Maléna
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Tensile behavior ,Bending behavior ,Ultra-High Performance Fiber Reinforced cement-based Composite (UHPFRC)
23. Comportement à la fatigue des dalles de roulement en béton armé renforcées avec du béton fibré ultra-performant
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Brühwiler, Eugen, Denarié, Emmanuel, Makita, T., and Bastien Masse, Maléna
24. Analytical modelling of R-UHPFRC - RC composite members subjected to combined bending and shear
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Bastien Masse, Maléna, Brühwiler, Eugen, and Makita, Tohru
- Abstract
The addition of a thin overlay of reinforced UHPFRC (R-UHPFRC) to a reinforced concrete (RC) element creates a composite member which can be used for the strengthening of an existing structure and in the design of new structures. With its strain hardening and softening behavior and high resistance in tension, the UHPFRC layer serves as an external tensile reinforcement contributing to both flexural and shear resistance of the RC element. The main failure modes of a composite section were identified during previous experimental campaigns. In this paper, experimental results on a composite slab strip are presented to demonstrate how the layer contributes to the shear resistance. Using this example, an analytical model to predict the behavior and calculate the resistance of a composite member is presented and applied.
25. RE:CRETE - Building out of concrete, without pouring concrete
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Grangeot, Maxence, Bastien Masse, Maléna, Brütting, Jan, Devènes, Julie Rachel, Küpfer, Célia Marine, and Fivet, Corentin
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Reuse ,Circular Economy ,Concrete ,Construction - Abstract
Concrete is the most ubiquitous construction material worldwide but also a major source of waste and CO2 emissions. Worse, it is too often crushed down prematurely for recycling or filling. Can’t we do better? We seek to reuse concrete from demolition sites by carefully sawing reinforced walls and slabs, hence generating a new circular supply chain. Reclaimed components come with their own history, their own imperfections and irregularities. Yet, they are a fully reliable construction material, amply capable of new structural feats. We designed and built the RE:CRETE footbridge, a unique post-tensioned arch that spans 10 meters, with 25 reused concrete blocks. The joints are made with regular mortar before post-tensioning. Loaded up to 1.8 tons, and deflecting less than 1.15mm, the footbridge performs just as any other one. This bridge is built out of concrete… without pouring any concrete. It opens up new pathways to drastically cut waste and CO2 emissions.
26. Le béton de réemploi, ressource territoriale à mobiliser
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Fivet, Corentin, Küpfer, Célia Marine, and Bastien Masse, Maléna
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Waste ,Demolition ,Circular Construction ,Reuse ,Concrete - Abstract
Plus que de tout autre matériau, le bâti suisse est fait de béton. Matériau aux nombreuses qualités, il est présent dans toute nouvelle construction, souvent en grande quantité. Malgré cela, des tonnes de béton sont quotidiennement démolies, pour des raisons plus proches de l'obsolescence des espaces qu'il crée que de sa propre dégradation. Ces démolitions exacerbent l'impact considérable de la mise en œuvre du béton sur l'environnement. Face à ce constat, un nouveau paradigme de construction permettrait de découpler obsolescence du bâti et demande en béton neuf : le réemploi d'éléments de béton, extraits par sciage des bâtiments voués à la démolition et réassemblés dans de nouvelles structures porteuses. L'approche n'est pas neuve, est déjà éprouvée, mais peine à se généraliser. Le territoire suisse rejette sans cesse du béton dévalorisé. Cette ressource sera-t-elle un jour exploitée à sa juste valeur ?
27. Matériaux rejetés et nouveaux défis
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Fivet, Corentin, Küpfer, Célia Marine, and Bastien Masse, Maléna
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construction ,état de lieux ,architecture ,réemploi - Abstract
Le réemploi des composants se présente comme une stratégie de durabilité prometteuse pour l’industrie de la construction, mais sa généralisation est-elle à portée de main ?
28. Reusability Assessment of Obsolete Reinforced Concrete Structural Components
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Devènes, Julie Rachel, Bastien Masse, Maléna, Küpfer, Célia Marine, and Fivet, Corentin
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Existing Structures ,Reuse ,Circular Economy ,Reinforced Concrete - Abstract
The production of concrete, the most widely used construction material, detrimentally affects the environment. Obsolete reinforced concrete (RC) load-bearing structures, even when still in good condition, are today prematurely crushed and landfilled or recycled into new concrete mixes. Little known and rarely implemented, the reuse of RC structural components is an alternative strategy towards more circularity in the construction industry. Since 2021, RC component reuse has been implemented in a series of construction and deconstruction projects in Switzerland. This paper identifies existing process sequences for RC-reuse projects and proposes one that involves a new assessment procedure to evaluate the reusability of the components early on and facilitate their future reuse planning. The paper discusses the application of this procedure to three deconstruction projects. Results are encouraging with regard to the durability of RC components. Almost 90% of the RC components of a building could be reused for new purposes with the same stability and exposure as in the donor building.
29. Strengthening the Chillon viaducts deck slabs with reinforced UHPFRC
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Brühwiler, Eugen and Bastien Masse, Maléna
- Subjects
resistance ,strengthening ,bridge deck slab ,composite section ,analytical model ,UHPFRC ,reinforced concrete ,rehabilitation ,casting method - Abstract
Located in Switzerland, Chillon viaducts are two parallel highway posttensioned concrete bridges built in the late 1960s. The concrete of the deck slabs of these bridges shows signs of early stages of the alkali-aggregate reaction (AAR), which will induce, in time, a decrease of the concrete strength. To insure structural safety for future traffic demands, it was decided to strengthen the slab by adding a layer of 40 mm of an Ultra High Performance Fiber Reinforced cement-based Composite (UHPFRC) material, reinforced with steel rebars. Strain-hardening UHPFRC, with its low permeability, is used as a waterproofing layer protecting the slabs from the water to reduce the rate of AAR. UHPFRC has excellent mechanical properties and also acts as an external tensile reinforcement for the slab, increasing its bending and shear resistance and extending the fatigue life. To investigate this increase in structural resistance, an analytical calculation is done using models previously developed based on extensive experimental campaigns. Finally, the choice of UHPFRC for strengthening was also the most efficient in terms of intervention duration and cost.
30. Punching Tests on R-UHPFRC-RC Composite Slabs without Shear Reinforcement
- Author
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Bastien Masse, Maléna
- Subjects
Composite slab ,Punching shear ,Ultrahigh performance fiber reinforced cement-based composite (UHPFRC)
31. Building structures made of reused cut reinforced concrete slabs and walls: A case study
- Author
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Widmer, Nicole, Bastien Masse, Maléna, Fivet, Corentin, Biondini, Fabio, and Frangopol, Dan M.
- Abstract
Reuse of reinforced concrete (RC) components reduces construction’s environmental impacts and waste. Rather than crushing the concrete of an obsolete structure, its components are saw cut and later reassembled in a new structure. The theoretical feasibility of this method is demonstrated through a case study: the design of a residential building structure that reclaims cast-in-place RC components from two 60-year-old office buildings scheduled for demolition. Parts of the source buildings are allocated to an optimal position in the target building using an algorithm that minimizes the need for strengthening. Construction details are developed for the slab-wall connections and the bracing system. An alternative conventional cast-in-place RC design is proposed for comparison, as well as a hybrid design balancing environmental and cost savings with technical readiness. The assessment of the designs confirms that reusing RC components allows saving up to 75% of greenhouse gas emissions for similar costs, as long as demolition and disposal of obsolete source material are considered.
32. Structural Behavior of R-UHPFRC - RC Composite Slabs
- Author
-
Bastien Masse, Maléna, Brühwiler, Eugen, and Denarié, Emmanuel
- Subjects
Near interface cracking ,Fiber orientation ,Critical shear crack ,Strengthening ,Composite slab ,Punching shear ,Fiber efficiency ,UHPFRC ,Tensile response - Abstract
The application on existing Reinforced Concrete (RC) slabs of cast-on-site Ultra-High Performance Fiber Reinforced cement-based Composite (UHPFRC) layers is an efficient reinforcement technique, currently spreading. The thin layer of UHPFRC, with or without steel rebars, serves as a tensile reinforcement for the RC slab, creating a composite element. This thesis combines material and structural engineering to study the behavior and resistance of two-way spanning composite slabs, with a certain focus on punching shear resistance. When analysing the behavior of composite elements, the effect of fiber orientation on the in-plane tensile response of the UHPFRC layer needs to be accounted for. Theoretical tools are derived herein to analyze the complementarity of fiber orientation in perpendicular directions and determine the average effect of fiber orientation on fiber efficiency at pull-out. A comprehensive material testing campaign on a strain-hardening UHPFRC is carried out on specimens with various thicknesses and casting processes. The most likely fiber orientation in a layer of UHPFRC for the casting method considered herein is finally estimated with the results of the theoretical and experimental work and a representative tensile response is scaled accordingly. An experimental campaign is carried out on six composite slabs without transverse reinforcement. The parameters of the tests include the thickness of the UHPFRC layer and the amount of reinforcement in it. The punching shear resistance of all composite slabs is higher than the resistance of the reference RC slab. The layer of UHPFRC increases the rigidity of the slab and provides added shear resistance to the cracked RC section by out-of-plane bending accompanied by limited or inexistent Near Interface Cracking (NIC) in the concrete section prior to failure. By doing so, it allows more deformation to take place in the RC section before punching shear failure. This results in rotations at maximum resistance close to what is observed for the reference RC slab. An analytical model is then developed to predict the global bending behavior of the composite slab and the punching shear resistance. A multilinear moment-curvature relation for composite sections is used to calculate the force-rotation curve of a slab. The intersection between this curve and a deformation based composite failure criterion predicts the punching shear resistance. This criterion combines the concrete and the UHPFRC layer contributions. The latter resists to punching shear by out-of-plane bending over a limited length. This mechanism induces tensile stresses perpendicularly to the interface with the concrete. The contribution of the UHPFRC layer to the punching shear resistance thus depends on the tensile strength of concrete. In the final section of the work, a description of the parameters influencing the shear resistance of composite elements is done. With the tools developed in this work, the effects of fiber orientation in a layer can be mastered and the analytical models allow to simply verify the resistance of a composite section.
33. Zürich Stadtspital Triemli Personalhäuser – Resource assessment of structural elements
- Author
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Devènes, Julie Rachel, Bastien Masse, Maléna, Küpfer, Célia Marine, and Fivet, Corentin
- Abstract
The Triemli Personalhäuser are three equal 15-story buildings located on the Zürich Triemli Stadtspital campus and erected between 1964 and 1969. Cast-in-place reinforced concrete (RC) slabs and walls form the building cores and their surrounding corridors. The rooms are arranged around these cores. The load-bearing intermediate walls, made of prefabricated masonry, support thin precast slabs used as permanent forms. A RC layer is cast over these precast slabs and connects the room slabs with the cast-in-place slabs of the corridors and cores. The self-supporting facade consists of precast RC panels. The City of Zürich plans the deconstruction of these three buildings, thus making available a large amount of RC elements composing the structure and the facades of these buildings. Little-known and rarely implemented, the reuse of concrete elements from obsolete buildings in new projects is a sustainable approach that promotes a circular economy. When reusing, the components of obsolete buildings are carefully dismantled without being crushed. They are then cleaned, possibly repaired or trimmed, and reused without many transformations in a new project, maintaining their shapes, technologies, and mechanical properties. In addition to maintaining the embodied energy and history of the reused components, reuse allows the construction industry to reduce demolition waste, greenhouse gas emissions, and material consumption. This report is a preliminary resource assessment and aims at inventorying and assessing all structural elements of the Triemli Personalhäuser, focusing on their potential value for reuse. Both precast and cast-in-place RC elements are included. They are part of the load-bearing structure or are self-supporting such as the precast facade elements. The proposed methodology allows identifying all properties needed to evaluate the potential for reuse of an element: geometry, material properties, current condition, aesthetics, accessibility, resistance, future durability and environmental impacts. After reviewing available reports and drawings on the buildings, onsite visits are carried out to complete the information and visually inspect the structural elements. During the inspection, the elements are assessed with regards to their suitability for reuse and their condition is classified into a five-grade scale. The investigations are completed with destructive and non-destructive testing of the material properties. Together, Buildings A, B and C are made up of approximately 7 000 m3 of materials constituting their load-bearing system, with approximately 2 500 m3 of precast concrete, 3 400 m3 of cast-in-place concrete and 1 100 m3 of masonry. Of this total, approximately 4% of the volume is dropped from the analysis due to the bad condition of the elements, namely the balcony slabs, the roof slab, and the external stairs. The other elements are in a good or acceptable condition and ae inventoried and analysed in detail. The inventoried elements are divided into 5 categories: (1) facade elements; (2) slab elements; (3) wall elements; (4) column elements; and (5) staircases. Each of these categories are subdivided into a certain number of element types for which a complete factsheet is prepared, including pictures, drawings and useful information on their condition. The volume and weight of each element types are given, as well as their share of the total material volume. The embodied global warming potential (in kgCO2eq) for fabrication and demolition of the elements is also calculated. The results of the investigation on material properties confirm sufficient compressive strength for all elements. The carbonation depths measured on the cores are lower than the cover thickness of the reinforcement. Thus, the concrete is not carbonated in the reinforcement areas and the risk of corrosion is kept low, insuring a good durability of the elements. This document should serve as a base for designing and planning future reuse applications for the concrete elements extracted when deconstructing the Triemli Personalhäuser. The information presented here will help the planners to prioritize the reuse strategy on the elements in the best conditions, with the largest volume share and thus with the largest embodied global warming potential.
34. Influence of an R-UHPFRC layer on the shear tranfer mechanisms of reinforced concrete elements
- Author
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Bastien Masse, Maléna and Brühwiler, Eugen
Catalog
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